Which Grass is Which Webinars

Learn the basics of grass identification and how to identify common prairie, woodland, weedy, annual, cool, and warm-season grasses found in Illinois through Which Grass is Which workshops.

Which Grass is Which Webinars 

Grasses play a big role in natural ecosystems — from controlling soil erosion to supporting pollinators to providing food for livestock — but telling one from another isn’t always easy. Land managers, farmers, naturalists, and gardeners want to know which grass is which, so you can manage undesirable grasses and promote desirable ones. Learn which grasses benefit wildlife or are potentially harmful if left untreated. 

Summer 2026 Live Workshops

The Which Grass is Which series is offered periodically as a live, interactive webinar hosted by Erin Garrett, Extension natural resources, environment, and energy educator. The sessions are recorded and available to watch on the Illinois Extension YouTube Account. 

These workshops are free, open to the public, and recommended for those working in the natural resource field and Master Naturalist volunteers. The series will not cover the identification of lawn grasses or the planting, care, or management of grasses.

Sign Up

  • July 28, Basics of Grass Identification and Identification of Common Woodland Grasses: Explore the basics of what it takes to identify grasses, including terms and characteristics. This workshop will also cover woodland grasses.  

  • July 29, Identification of Common Prairie Grasses: Prairies are dominated by grasses. From side oats grama to switchgrass, learn about the variety of grasses found in Midwestern prairies.  

  • July 30, Identification of Common Nuisance Grasses: Commonly found on roadsides and disturbed areas, it is important to be able to tell these nuisance grasses apart from more desirable species.  
short clumps of grass in woods

Woodland Grass Identification

Here's your introduction to grass identification, with terms to know and tricks. Then we dig into the identification of 15 species of woodland grasses in Illinois. While grasses may not be a group of plants you expect to find in abundance in a wooded area, there are still many species of grasses that can be found in our woodlands.
prairie grass

Prairie Grass Identification

Prairies are dominated by grasses, and what a diversity of them there is! We’ll start to piece out the 18 different species of grasses found in Illinois prairies.
nuisance grass

Nuisance Grass Identification

There are 22 nuisance grass species in Illinois commonly found on roadsides and in other disturbed areas. While we may not want to see these grasses out in the field, it’s important to know how to tell them apart from more desirable species.
clump of rye grass seed heads

Cool-Season Grass Identification

In spring, cool-season grasses emerge, grow, and flower. These grasses, both native and non-native species, play an important role in providing habitat and food sources in the early spring before warm-season grasses emerge and flower in the summer. 
warm season grass

Warm-Season Grass Identification

Over the summer, warm-season grasses emerge, grow, and flower. These native and non-native grasses provide habitat and forage for wildlife. You might find these grasses while out hiking or along roadsides.
yellow foxtail spike

Annual Grass Identification

While many grasses are perennial and return year after year, other grasses are annual and only live for one year. Many of these annual grasses emerge, grow, and flower in the summer, while others grow in the winter and spring. Learn how to identify 19 different annual grasses in Illinois, including both summer and winter annuals.